Hydro-massage bathtubs provide a therapeutic massaging action by delivering water through a plurality of jets in the tub wall to create a circulating flow of turbulent water. The tub water is circulated through a heater and pump back to the tub through the jets to provide a warm circulating flow. Air can be added to the circulated flow at a controlled rate to increase the turbulence and massaging action of the water exiting from the jets.
As with any such system having electricity in proximity to water, all electrical components must be isolated from the user to prevent injuries due to electrical shock. To prevent accidents, extraordinary efforts are made to provide electrical components and wiring, which are completely isolated by using mechanical controls linked to electrical circuits. However, these devices, though effective, are not as stable, efficient and reliable as desired.
An additional problem with these types of control systems is that of inadvertent operation when the the water level is low. Such occurrences can result in the jets splattering water throughout the area resulting in a damaging, messy and unsanitary condition, or the pump running dry and burning out the shaft seals.
Some systems employ level sensors to make a system inoperable if levels are below a pre-selected level, however, they suffer from a number of problems. One such system uses a float which can bind, thereby preventing operation. Further, such floats being in contact with dirty trashy water can interfere with the system operation requiring frequent maintenance. Other systems use pistons which can freeze or stick, thereby interfering or preventing operation. A system that uses no hinged parts, pistons or floats would be advantageous as it could be isolated from the water used in the system resulting in improved stability, reliability and efficiency.
These systems also suffer from frequent electrical failure, due to the corrosive environment created when there is a high degree of moisture present. System components often corrode and fail and require replacement or repair.
It is therefore one object of the present invention to provide a hydro-massage bathtub control system having a reliable, stable and safe design by using all solid-state construction.
Still another object of the present invention is to provide a hydro-massage tub control system having improved electrical controls.
Yet another object of the present invention is to provide a hydro-massage tub system having an operating switch system minimizing the potential for failure by using an electrically isolated switch for safety.
Another object of the present invention is to provide a hydro-massage tub control system having a water level sensor safety system which will prevent operation below a pre-selected water level.
Still another object of the present invention is to provide a hydro-massage tub control system having an improved heater design using all solid-state circuits.
Yet another object of the present invention is to provide a heater system for a hydro-massage tub, providing proportional control to the heater for improved efficiency, stability and temperature regulation.
Yet another object of the present invention is to provide a hydro-massage tub system with a heater system having a fail-safe thermal fuse and fail indicator.
Another object of the present invention is to provide a hydro-massage control system having a heater control minimizing overheating to provide more accurate operation. The proportional control of power to the heating system provides very little potential overshoot and maintains temperature at a very reliable pre-selected level.
Still another object of the present invention is to provide a hydro-massage tub control system having a modular construction, connected by modular cords and plugs, allowing quick disconnect and replacement or repair of solid state circuits.
Another object of the present invention is to provide a water level sensing safety system for a hydro-massage tub having a positive acting optical switch isolated from the water in the tub by an air column.
Still another object of the present invention is to provide a water level sensor safety system for a hydro-massage control system having a positive acting switch isolated from tub water, that operates almost instantaneously to stop the system when the water drops below a pre-selected level.
Another object of the present invention is to provide a water level sensing safety system that avoids the use of unreliable mechanical or hinged parts.